Is (attempting) logic with theists a waste of time?

Atheists tend to put a lot of stock in the emperical method and in logic. One cannot disprove God exists using the emperical method. You might reply: But I can't disprove a giant purple frog on Mars controls the universe, either. Granted, one can never disprove any given thing exists. The atheistic position denying God's existence, if based on the emperical method, is absurd. Why do I say that? In order to prove the ertion No God exists experimentally, one would need to comprehensively know all of reality. Comprehensive knowledge of reality is called omniscience. One would need to be omniscient in order to prove there is no God, but if one were omniscient one would, by definition, already be God